1. Technical Field
The present invention relates to an image communicating apparatus.
2. Related Art
In an existing facsimile communication through a G3 (Group3 Facsimile) machine, a decision of a transmission error line is made if the number of conversion dots between EOLs (End Of Line) is not coincident with the number of dots determined by T.4 at a receiving side, and RTP (Real Time Protocol) or RTN (Retrain Negative) is sent when the transmission error line is counted so that a threshold is exceeded. If data to be transmitted are lost or a data change is caused by a short break or a noise, an inaccuracy of the number of dots between the EOLs occurs. For this reason, it is possible to make a detection of a transmission line.
Even if the data loss or data change is caused continuously for a certain period so that data corresponding to several lines cannot be received normally, moreover, a probability that start and end parts of a data abnormality will be exactly applied to a break of the line is low on a probability theory basis. Therefore, it is possible to make a detection of an error of at least one or two lines in front and rear parts.
On the other hand, with a spread of internet, there is realized a facsimile communication via an IP network for putting a facsimile signal (including image information) on an IP (Internet Protocol) packet using a protocol referred to as IFP (Internet Facsimile Protocol) and transferring them in a real time based on a T.38 method (a real time transferring method) recommended by ITU-T(International Telecommunication Union Telecommunication Standardization Sector).
In the facsimile communication using the IP network based on the T.38 method, it is supposed that a method of carrying out packeting every line or several lines and transmitting the packet in a non-ECM (Error Correction Mode) communication is a mainstream. In the packet transmitting method, however, data are lost (or cancelled) on a packet unit over the IP network in many cases. When the loss of the packet occurs during a receipt of image information, the image information is extracted clearly in an exact break of the line. As a result, even if the data are lost, it is impossible to carry out counting for a transmission error line.
In the case in which a communication is continuously carried out even if the packet is lost, there is the following possibility as a result. More specifically, although a received image has a lack so that a length of the image in a secondary scanning direction is small, a result of the receipt is obtained as a normal end. For this reason, it is impossible to recognize that an information transmission between users has a lack, resulting in troubles (a misrecognition).